Zenith Z-171 Series Service Manual page 77

Page
6-3
System Checkout and Troubleshooting
Table 6-1 (continued): Error Messages
MESSAGE POSSIBLE PROBLEM
+ + +DISK ERROR: Bad disk controller! + + +
+ + +DISK ERROR: DM! overrun error! + + +
These messages usually indicate a malfunction of the disk
controller circuit, but may also appear because of other
defective circuits in the system. If any nonstandard boards
have been installed, they should be suspected first.
+ + +DISK ERROR: Sector not found! + + +
+ + +DISK ERROR:
CRe
er;ror! + + +
+ + + DISK ERROR: Invalid address mark detected! + + +
SetUp
These messages normally indicate that an operating system
was not found on the selected drive disk, or there
may
be a faulty drive. First
try
a different disk.
If
this error occurs
often, it may be necessary to have the drive aligned or
the disk controller circuit checked.
Refer to Chapter 1 for a list of the tools and equipment required for
the following procedure.
1.
Disconnect all peripherals from the computer.
2. Remove any circuit boards not supplied by Zenith Data Systems.
3. Verify that power (120 VAC) is available at the power outlet being
used by the computer.
4. Plug the AC adapter into the computer and then into the poV/er
outlet.
If
no failures are found, a standard computer will not require any disassen-
bly when using the troubleshooting procedure.
If
a problem is discovered,
it will be necessary to disassemble the computer to further
troublesh~OIt
the system. Refer to Chapter 4 for the necessary disassembly instructions.